Priming liquid applicator for offset rotary printing machines



July 10, 1962 A. G. R. GATES 3,043,215

PRIMING LIQUID APPLICATOR FOR OFFSET ROTARY PRINTING MACHINES Filed Jan.27, 1961 3 Sheets-Sheet l Attorney July 10, 1962 A, e. R. GATES PRIMINGLIQUID APPLICATOR FOR OFFSET ROTARY PRINTING MACHINES 5 Sheets-Sheet 2Filed Jan. 27, 1961 w ms n 6 m k E a A July 10, 1962 A. G. R. GATES3,043,215

PRIMING LIQUID APPLICATOR FOR OFFSET ROTARY PRINTING MACHINES Filed Jan.27, 1961 3 Sheets-Sheet 3 Inventor ALEERT 616- 6A 755 Attorney SAM-3,215Plsiiffiifl rronm APP ICATGR F61 EBFFSET RGTAR PRINTENG MAEHHHZS AlbertGeorge Ronald Gates, Edmonton, London, England, assignor to GestetnerLimited, London, England, a British company Filed Jan. 27, 1961, Ser.Na. 85,311 Claims priority, application Great Britain Feb. 1, 1969 21Claims. (Cl. 1011 i3) This invention concerns oifset rotary printerswhich conventionally comprise a plate cylinder, a blanket cylinder, animpression cylinder, at delivery cylinder and means for applying ink andWater to the plate cylinder.

In offset rotary printers, it is necessary, before commencement of theprinting operation, to apply to the plate an aqueous ink repellantsolution which desensitizes the non-image areas of the plate. Thisoperation is known as priming.

Priming of the plate is usually carried out manually by the operator ofthe machine wiping a dampened sponge or pad over the plate. Such amanual operation is time consuming and unpleasant for the operator.

It is known to use, for dampening a plate during th printing operation,apparatus comprising a damping liquid applicator roller engaging .theplate cylinder and supplied with damping liquid from a reservoir. It isalso known to use two such applcator rollers engaging the plate cylinderat angularly spaced positions therearound and rotating with the sameperipheral speed. Such known apparatus for dampening a plate during theprinting operation cannot be satisfactorily used for priming the platesince it is absolutely necessary that the plate be completely covered bythe priming liquid and these known apparatus do not provide a sure andeffective application of liquid to all parts of the plate. For thisreason, the priming liquid is up to the present time usually appliedmanually, although it is in some instances applied mechanically by apad.

It is an object of this invention to provide means for effecting whenrequired, the priming of the plate quickly, efliciently and without theoperator of the machine having to handle the priming liquid.

According to this invention, I provide apparatus for use in priming theplate of the plate cylinder in an oiiset rotary printer, such apparatusbeing movable between a priming position and an out-of-the-way positionand comprising two plate cylinder priming liquid applicator rollersengaging the plate cylinder at angularly spaced positions therearound,such apparatus being characterised in that the two rollers, whenengaging the plate cylinder have different peripheral speeds.

The use of two rollers having diiierent peripheral speeds ensures a firmand even priming of the plate.

Preferably, the leading roller is arranged to be rotated at a lowerspeed thanthe trailing roller.

Preferably, the two rollers are coupled together so that one isautomatically driven on rotation of the other and such coupling isconveniently provided by a chain engaged over sprockets on spindles onwhich the rollers rotate. The differential rotation of the two rollersmay, with this construction, be achieved by using sprockets of differentsizes and having different numbers of teeth.

When the machine is using short paper plates, e.g. for system work, andthe trailing end of the paper plate is free and not secured to the platecylinder, the faster rotation of the trailing roller causes the paperplate to buckle between the positions of the rollers, and liquid isapplied by the trailing roller to the part of the cylinder which will,in use of the machine, lie beneath the trailing marite' rates atesby'the leading roller, the trailing marginal portion of the paper plateis adhered to the cylinder. Such adherence prevents the trailing end ofthe paper plate from flapping as the plate cylinder rotates and frombeing soiled, e.g. by contact with inking rollers of the machine, asoccurs in conventional offset printers when used for systems work withshort paper plates.

In order that this invention may more readily be understood, and furtherfeatures appreciated, one embodiment of the same will now be describedby way of example, with reference to the accompanying drawings, inwhich:

FIGURE 1 is a side elevation of apparatus according to this invention,such apparatus being shown in its damping position;

FIGURE 2 is a fragmentary plan view of the apparatus of FIGURE 1; I

FIGURE 3 is a section on the line III-I1l of FIG- URE 2;

FIGURE 4 is a side elevation of the apparatus in its out-of-the-wayposition; and

FIGURE 5 is a fragmentary exploded view illustrating the mounting of thepriming liquid applicator rollers.

The embodiment illustrated comprises apparatus for attachment to aconventional offset rotary printer for the purpose of priming the plateon the plate cylinder 1 of such machine before commencement of theprinting operation. The apparatus is mounted on a rotatable shaft 2extending between two spaced side members 3 which are rigidly connectedby cross bars i. Each of the side members 3 is carried by an arm 5adapted to be attached to across the machine parallel to the axis of theplate cylinmoves the locking member} in a direction towards the.

ginal portion of the paper plate so that, when the buckled part of thepaper plate is finally pressed on to the cylinder der. I The apparatuscomprises two side plates 6 which are parallel to the side members 3 ofthe'apparatus and are mounted on the'rotatable shaft 2, the lattercarrying at one end a handle 7 by which the shaft can be rotated to movethe apparatus towards the plate cylinder 1 into a priming position asshown in FIGURES 1, 2 and 3, against the action of tension springs 8which are connected betweeneach side plate .6 and the adjacent sidemember 3 and which normally. bias the apparatus to an out-of-the-wayposition shown in FIGURE 4.

The handle 7 carries a catch for locking the apparatus in itsout-of-the-way position, such catch comprising a locking member 9extending alongside the handle 7 and having at its outer end a fingerpiece 10 and at its inner end a locking peg 1-1 engaged in a slot 12 inthe adjacent side member 3. The locking member 9 also has at positionsintermediate the finger piece 10 and peg 11 two 1ongitudinally spacedelongated slots 13, through which pass guide pins 14 carried by a plate15 on the side of the handle 7 opposite to the member 9, and a peg 16projecting into a slot 17in the handle'housing a compression spring 18.

The arrangement is such that, in the priming position of the apparatus,the locking peg 11 is located at the lower end of the slot 12, the guidepins =14- are located at the forward ends of the elongated slots 13 andthe peg 16 is in a position spaced from the adjacent end of 'slot 17 andcompresses the spring 18. When the handle 7 is raised to move theapparatus into its out-of-the-way position, the compression spring 18pressing on the peg 16 shaft 2 so that the locking peg 11 engages in atransverse branch of the slot 12 at the upper part thereof and locks themember 9 in this position and thereby locks the apparatusin itsout-of-the-way position, To release the apparatus for downward movementinto its priming position;

the member 9 has to be retracted again against the action of spring 18by a pull exerted on the finger piece 10.

avoids undue vibration of the apparatus during operation of the machine.

Between the side plates 6" of the apparatus extend two priming liquidapplicator rollers 19 and 20. mounted for rotation on parallel axesparallel, to the axis of the plate side plates 6 are connected togetherby a cross member 23 secured to the plates by screws 24. Removal of thescrews 24 enable the side plates to, be moved apart 'to withdraw thepins 22 from the rollers for replacement of the latter or of acoveringsleeve with which one or both rollers may be provided. a I Atone end of the rollers 19 and Ztleach pin 22 carries a sprocket 25 andan endlesschain 26 isengaged around the two sprockets'so that rotationof one roller causes rotation of the other. 7 r a The two rollers arearranged to rotate at difierent speeds bymaking the roller sprockets ofdiiferent sizes and provided with adiiferent, number of teeth. In theembodiment illustrated, the sprocket 25 associated with the leadingroller 19 hasrnine teeth, whilst the sprocket 25 associated with thetrailing roller 2% has eight teeth so that the leading roller l9 rotatesat a lower speed than the trailing roller 20. If desired, the sprocketsmay be arranged to be removable and interchangeable with tray has anaperture 30 adjacent one edge and the wick 29 projects through suchaperture so that, when liquid 'in the reservoir is catsuch edge, suchliquidis in contact with the wick and is ledto the pad therebelow.Ifdesired,wick 29 could be dispensed with and thevpad 28 arranged so astoibe in direct communication with the liquidin the 'reservoirthroughthe aperture 30. a a

The reservoirhas projecting outwardly-at each side thereof two pins 31which pass throughguide slots 32 in the adjacentside member 3 of theapparatus and which control' the movementof thereservoir whengtheappa:

ratus' is moved relatively to the side'rnembers. I 'At its lower part,the reservoir carries a roller 33 resting .onthe upperedges of the sideplates 6. These upper edgeslareiso shaped that, when the apparatus:moves to its out-of-theway position, the side plates 6 exert a cammingaction on the reservoir and the latter moves rela- V tively to the sideplates and rollers carried thereby, such movement being guided by thepins 31 engaged in the slots 32. Thearrangement is such that, in theout-of-the{ way position of the apparatus, the pad 28 below thereservoiris out of contact with the two rollers 19 and 20 and the base of :thereservoir tray 27 slopes downwardly awayfi'om the aperture 30thereinand, in the damping position of the apparatus, the pad 28 engages therollers and the reservoir is orientated so that the base of thereservoir tray slopes downwardly towards the aperture 30.

It will be appreciated that the quantity of liquid in the reservoirisarranged to be such that, when the apparatus is in itsout-of-the-wayposition the liquid does not extend to the aperture 30. w v As will beclearly understood from the foregoing, when the apparatus is in itsout-of-the-way position, the pad 28 beneath the reservoir isoutofcontactwith thepriming liquid applicator rollers H and 20 and no liquidis supplied to the pad from the reservoir, but, when the apparatus ismoved downwardly by depression of the handle 7, the reservoir tilts tosupply liquid to the pad 28 and the latter moves to engage the rollerswhich are caused to bear against the plate on the plate cylinder so asto rotate when the latter rotates and to prime the plate.

The priming liquid applicator rollers may bemade of, or have a coveringof, rubber, felt, or any other suitable material and the: two rollersmay be of similar or dissimilar form. The rollers, being readilyremovable, may be interchanged or replaced so that the apparatus may beadjustedto suit different machine operating conditions. When short paperplates are used, we have found that a convenient arrangement is to havethe leading roller 19 felt covered and the trailing roller 29 formed ofrubber.

Conveniently, as shown, the pins 22 carrying the trailing roller 2!; maybe mounted in elongated slots 34 in the side plates 6 and be springpressedto urge thisroller firmly into engagement with the plate on theplate cylin der. in FIGURES 1 to 4, a torsion spring 35 carried by apost 26 is used to provide this spring pressure, Alternatively,acompression spring carriedby theappropriate' side plate 6 and bearingon the appropriate pin 22 may be used.

I claim: I,

1. An oilset rotary printing machine comprising a machine frame, a platecylinder carried by said frame for rotation about a horizontal axis, amounting fixed relatively to said frame, a primingliquid applicatorroller, support means carryingsaid roller for rotation about an axisparallel to the axis of the plate cylinder, means mounting said supportmeans on said mounting for pivoting thereon about an axis parallel tothe axes of the plate cylinder and roller between an operative positionin which the said'roller engages the surface of the plate cylinder andan out-of-the-way position in which the. said roller is spaced from suchsurface, a reservoir for priming liquid, a base to said reservoir havingan aperture along one edge thereof, wick means carried below the saidreservoir base and projecting upwardly through the said aperturetherein, means mounting the said reservoir on said support means so asto be'movabl'e relatively to the roller, and means on said reservoirco-operating with the said support means and said mounting and causingmovement of the reservoir relatively to the rollersuch that, when thesupport means is in its operative position,.the said wick means engagesthe surface of the rollerand the base 'of the reservoir is inclineddownwardly towards the aperture therein and, when thesupport means is inits out-of-theaway position, the said wick means is out of contact withthe surface of the roller and the base of the reservoir is inclined 3.The offset rotaryprinting machine specified in claim 2, and including ahandle by which the support means may be moved between its operative andout-of-the-way positions, a spring loaded catch carried by said handleand a locking peg on said catch co-operating with a slot in saidmounting for locking the support meansin its out-ofthe-way position. a

4. In an offset rotary printing machine, "appartus for priming theplate-on the plate cylinder such apparatus comprising two priming liquidapplicator rollers, means mounting said rollers for movement between anoperative position in which the rollers'engage the plate cylinder atangularly spaced positions therearound and an out-ofthe-way position inwhich the rollers are spaced from'the ,plate cylinder, means couplingthe rollers and constrainpriming liquid from the reservoir to thedamping rollers in the operative position of the latter.

5. The apparatus specified in claim 4, and comprising a sprocketassociated with each of said rollers, the sprocket associated with theleading roller having a greater number of teeth than that sprocketassociated with the trailing roller, and a chain engaged around the saidtwo sprockets.

V 6. The apparatus specified in claim 4 and comprising means mountingthe reservoir and wick means for movement relatively to the primingliquid applicator rollers between a position in which the wick means isin contact with the rollers when the support means is in its operativeposition and a position spaced from the priming liquid applicatorrollers when the support means is in its out-ofthe-way position.

I 7. An ofiset rotary printing machine comprising a machine frame, aplate cylinder carried by said frame for rotation about a horizontalaxis, a mounting fixed relatively to said frame, two priming liquidapplicator rollers, support means carrying said rollers for rotationabout axes parallel to the axis of the plate cylinder, means mountingsaid support means on said mounting for pivoting thereon about an axisparallel to the axes of the plate cylinder and said rollers between anoperative position in which the said rollers engage the surface of theplate cylinder at angularly spaced positions therearound and anout-of-theway position in which the said rollers are spaced from suchsurface, a reservoir for priming liquid, a base to said reservoir havingan aperture along one edge thereof, wick means carried below the saidreservoir base and projecting upwardly through the said aperturetherein, means mounting the said reservoir on said support means so asto be movable relatively to the said rollers, and means on saidreservoir co-operating with the said support means and said mounting andcausing movement of the reservoir relatively to the rollers such that,when the support means is in its operative position, the said wick meansengages the surface of the rollers and the base of the reservoir isinclined downwardly towards the aperture therein and, when the supportmeans is in its out-of-the-way position, the said wick means is out ofcontact with the surface of the rollers and the base of the reservoir isinclined downwardly away from the aperture therein.

8. The offset rotary printing machine specified in claim 7, andincluding means for locking the support means in its out-of-the-wayposition.

9. The offset rotary printing machine specified in claim 8, andincluding a handle by which the support means may be moved between itsoperative and out-of-the-way positions, a spring loaded catch carried bysaid handle and a locking peg on said catch cooperating with a slot insaid mounting for locking the support means in its out-of-the-wayposition.

10. The offset rotary printing machine specified in claim 7, wherein thesaid means on said reservoir co- Operating with the said support meansand said mounting comprise pegs on said reservoir engaged in slots insaid mounting and a roller on said reservoir resting on a cammingsurface of said support means.

11. The offset rotary printing machine specified in claim 7, andcomprising two spaced side plates providing said support means, across-member extending between said side plates, means securing saidside plates readily removably to said cross-member and pins journalledin said side plates and mounting the said rollers for rotation byengaging in axial bores in the ends of the rollers.

12. An offset rotary printing machine comprising a machine frame, aplate cylinder carried by said frame, a mounting fixed relatively tosaid frame, two priming liquid applicator rollers, support meanscarrying said rollers for rotation about axes parallel to the axis ofthe said plate cylinder, such support means being carried by saidmounting for pivoting thereon between an operative position in which thesaid rollers engage the surface of the plate cylinder at angularlyspaced positions therearound and an out-ofthe-way position in which thesaid rollers are spaced from said surface, 'a reservoir for primingliquid, means mounting said reservoir on said support means so as to bemovable relatively to the rollers, means on said reservoir co-operatingwith said mounting and said support means causing and guiding movementof the reservoir relatively to the rollers when the said support meanspivots relatively to the said mounting, wick means communicating withthe interior of the reservoir and contacting the surface of the rollerswhen said support means is in its operative position, and means couplingthe said two rollers and constraining the leading roller to rotate at alower speed than the trailing roller.

13. The oifset rotary printing machine specified in claim 12, andcomprising a sprocket associated with each of said rollers, the sprocketassociated with the leading roller having a greater number of teeth thanthat sprocket associated with the trailing roller, and a chain engagedaround the said two sprockets.

14. An offset rotary printing machine comprising a machine frame, aplate cylinder carried by said frame, a mounting fixed relatively tosaid frame, two priming liquid applicator rollers, support meanscarrying said rollers for rotation about axes parallel to the axis ofsaid plate cylinder, such support means being carried by said mountingfor pivoting thereon between an operative position in which the saidrollers engage the surface of the plate cylinder at angularly spacedpositions therearound and an out-of-the-way position in which the saidrollers are spaced from said surface, a reservoir for priming liquid,means mounting the said reservoir on said support means so as to bemovable therewith, Wick means, means mounting the latter on said supportmeans so as to be movable relatively to the rollers between a positionin which the wick means is in contact with the rollers when the supportmeans is in its operative position and a position spaced from therollers when the support means is in its out-of-the-way position, andmeans coupling the said two rollers and constraining the leading rollerto rotate at a lower speed than the trailing roller.

15. The ofiset rotary printing machine specified in claim 14, andcomprising a sprocket associated with each of said rollers, the sprocketassociated with the leading roller having a greater number of teeth thanthat sprocket associated with the trailing roller, and a chain engagedaround the said two sprockets.

16. An offset rotary printing machine comprising a machine frame, aplate cylinder carried by said frame for rotation about a horizontalaxis, a mounting fixed relatively to said frame, two priming liquidapplicator rollers, support means carrying said rollers for rotationabout axes parallel to the .axis of the plate cylinder, means mountingsaid support means on said mounting for pivoting thereon about an axisparallel to the axes of the plate cylinder and of said rollers betweenan operative position in which the said rollers engage the surface ofthe plate cylinder at angularly spaced positions therearound and anout-of-the-way position in which the said rollers are spaced from suchsurface, means constraining the rollers to rotate at differentperipheral speeds in the operative position of the support means, areservoir for priming liquid, a base to said reservoir having anaperture along one edge thereof, wick means carried below the saidreservoir base and pro iecting upwardly through the said aperturetherein, means mounting the said reservoir on said support means so asto be movable relatively to the rollers, and means on said reservoirco-operating with the said support means and said mounting and causingmovement of the reservoir relatively to the rollers such that, when thesupport means is in its operative position, the said wick means engagesthe surface of the rollers and the base of the reservoir is inclineddownwardly towards the aperture therein and, when the support means isin its out of the way position, the said wick means is out of contactwith the surface of the rollers and the base of the reservoir isinclined downwardly away from the aperture therein.

"l7. Theofiset rotary printing machine-specified in means may he movedbetween its operative and outof-thewayposi-tions, a spring loaded catchcarried by said handle and a locking peg on said catch co-operating with-a slotin said mounting for locking the support means in itsout-of-the-way position.

19. In an ofiset rotary printing machine, apparatus for applying apriming liquid to the plate on the plate cylinder, such apparatuscomprising two priming liquid applicator rollers, means 'mounting saidrollers for movement between an operative position in which the rollersengage the plate cylinder at angularly spaced positions therearound andan OUFOf-thG-WQY position in which the rollers are spaced from the platecylinder,

' -means constraining the rollers to rotate at different peripheralspeeds in the operative position of the rollers,

a reservoir for priming liquid, and wick means leading liquid from thereservoir to the rollers in the operative position ofthe latter.

20. .The apparatus specified in claim 19 and comprising means mountingthe reservoir and wick means for movement relatively to the rollersbetween a position in which the wick means is in contact with therollers when the latter are in said operative position and a posi-'out-of-the-Way position.

21. An otfset rotary printing machine comprising a machine frame, aplatecylinder carried by, said frame, a mounting fixed relatively tosaid fir ame, two priming liquid applicator rollers, support meanscarrying said rollers for rotation about axes parallel to the axis ofthe" plate cylinder, such support means being carried by said mountingfor pivoting thereon between an operative position in which the saidrollers engagethe surface of the plate cylinder at angularly spacedpositions therearound and an Out-Of-ihG-WHY position in which the saidrollers are spaced from such surface, means constraining said rollers torotate at ditferent peripheral speeds when the support means is in saidoperative position, a reservoir for priming liquid, means mounting thesaid reservoir on said support means so as to be movable relatively tothe rollers, and means on said reservoir cooperating with the saidsupport means and said mounting and causing movement of the reservoirrelatively to the rollers such that, when the support means is in itsoperative position, the said wick means engages the'surface oftherollers.

References Cited in the file of this patent UNITED STATES PATENTS

